lack annealed wire is rust proof within 6 months without any oil coating. The tensile strength is 300-400 Newton per square millimeter. Black annealed wire sizes: Wire diameter ranges from 0.70mm to 5.5mm. Application: Black annealed wire is mainly used as industrial wire, construction wire, industrial bale tie wire and constructional tie wire, etc. Packing: Different coil diameter or coil weight available for customers' choice